Trifocal diffractive intraocular lenses (IOLs) provide optimal near vision, while extended depth of focus IOLs are suitable for patients seeking good intermediate vision following bilateral cataract surgery, according to research published in Eye.
Researchers enrolled 79 participants in a study to compare visual outcomes following bilateral IOL implantation. Participants were randomized to 1 of 3 IOLs: a single piece non apodized trifocal diffractive IOL (n=26), a preloaded single piece hydrophilic trifocal diffractive IOL (n=27), or an extended depth of focus design (n=26). The team evaluated monocular uncorrected intermediate visual acuity (UIVA) at 80 and 60 cm, monocular uncorrected near visual acuity (UNVA) and distance-corrected near visual acuity (DCNVA) at 40 cm, monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE) refraction, binocular defocus curve, contrast sensitivity, photopic phenomena, and spectacle independence during a 6-month postoperative exam. No statistically significant differences were noted among the groups at baseline.
Overall, UIVA at 80 cm was significantly better among patients fit with the preloaded single piece hydrophilic and extended depth of focus designs compared with those implanted with the non apodized diffractive design. The UIVA at 60 cm was significantly better among participants wearing extended depth of focus and non apodized diffractive lenses compared with the preloaded single piece hydrophilic design. The extended depth of focus lenses had a statistically worse DCNVA compared with both trifocal diffractive optic designs, according to the report.
At a defocus of −2.50 diopters (D), the near visual acuity was comparable among trifocal diffractive designs and significantly better compared with the extended depth of focus IOL. Binocular photopic and scotopic contrast sensitivity outcomes were comparable among the 3 groups (P >.05) at all spatial frequencies.
Researchers acknowledge that no single IOL can produce optimal outcomes in all patients. “With the availability of many presbyopia-correcting IOLs, knowing the behavior of each IOL is essential for choice of the best IOL design compatible with patient’s needs and expectations, for achieving the best satisfaction,” according to the investigators.
Study limitations include a short follow-up period and a subjective assessment of photic phenomena and quality of vision.
Torky MA, Nokrashy AE, Metwally H, Abdelhameed AG. Visual performance following implantation of presbyopia correcting intraocular lenses. Eye. Published online August 8, 2022. doi:10.1038/s41433-022-02188-y